renamed: signals.py -> signals/transfer_endpoint.py

new file:   signals/__init__.py

netbox_dns_bridge/signals/__init__.py

@@ -0,0 +1 @@
+from . import transfer_endpoint

netbox_dns_bridge/signals/transfer_endpoint.py

@@ -0,0 +1,37 @@
+from django.db.models.signals import pre_save, post_save
+from django.dispatch import receiver
+from netbox_dns.models import Zone
+from . import catalog_zone_manager as catzm
+
+
+@receiver(pre_save, sender=Zone)
+def zone_pre_save(sender, instance, **kwargs):
+    """
+    Cache the old name so post_save can see if it changed.
+    """
+    if instance.pk:
+        try:
+            instance._old_name = sender.objects.only("name").get(pk=instance.pk).name
+        except sender.DoesNotExist:
+            instance._old_name = None
+    else:
+        instance._old_name = None
+
+
+@receiver(post_save, sender=Zone)
+def sync_catalog_zone_identifier(sender, instance, created, **kwargs):
+    """
+    Ensure CatalogZoneMemberIdentifier exists for each Zone
+    and keep its identifier in sync.
+    """
+    if created:
+        # Create the related object on Zone creation
+        catzm.update_member_identifier(instance)
+    else:
+        old_name = getattr(instance, "_old_name", None)
+
+        # If the name did not change, do nothing
+        if old_name == instance.name:
+            return
+
+        catzm.update_member_identifier(instance)